We try to sign a passive content (data only [1]) within the new interface on symbiansigned.com.
But we only got a exception: "de.trustcenter.sistools.execptions.SisSignatureFormatExeption: Corrupt SIS file" on submissions.

We have rechecked our sis-content-file with is correct (with VerifySymbianSigned v2.4):
File format : SISX (V9)
SIS file : verylongname_3rd_contentname.SIS
Symbian Signed : No
Developer Certificate Signed : No
ACS Publisher Signed : Yes
ACS Publisher Supplier : TCT (1 found)
Unknown Certifictaes : 0

Any ideas, why this submission failes?

[1] pkg file contains is TYPE=SP (SISPATCH)